Top closure for leakproof dry cells



June 25, 1946. H, J SMWHBACK 2,402,784

TOP CLOSURE FOR LEAKPROOF DRY CELLS Filed Aug. 29, 1942 i I 111510 j 1 I jg 4 ii; H 1,' 9 (la "l r i 1 w 1 MZS.

Patented June 25, 1946 TOP CLSURE FOB LEAKPROOF DRY CELLS Howard J. Smithback, Madison, Wis., assignor to Ray-O-Vac Company, a corporation of Wisconsin Application All-gust 29, 1942, Serial N0. 456,613

(Cl. ISG-133) 2 Claims. 1

This invention relates to an improved top structure for a leak-proof dry-cell of the type commonly used in ilash lights.

'I'he primary object of the invention is to provide a strong inexpensive construction o! attractive appearance wherein the metal top closure not only is insulated from the zinc electrode but also holds the insulating material in proper position and is capable of withstanding internal pressure which may be in the neighborhood of 100 pounds per square inch.

Leak-prooi cells of the type now in common use have a steel jacket and accordingly are more expensive to manufacture than the common type of cell using a paper iacket. The present invention has many of the advantages oi' the steel jacket construction but due to the improved top structure is able to seal up the paper jacket so that the cell is substantially leak-prooi and of greatly enhanced appearance.

A further object of the invention is to provide an improved metal top which may be readily installed and will cooperate with the sheathed zinc electrode to provide a mechanical structure of great strength.

The invention is illustrated in a preferred embodiment in the accompanying drawing, in which Figure l is an elevational v,yiew, partly in section, showing the improved construction; Figure 2, a top plan viewr of the cell; and Figure 3, an exploded view showing how the parts of the casing are assembled.

In the embodiment illustrated, the usual hollow cylindrical zinc electrode 4 may be in the form of a cup containing a centrally disposed carbon electrode l surrounded by a bobbin of depolarizing mix l immersed in electrolyte 1.

D Preferably an insulating washer l is provided 1n the upper portion of the zinc electrode and snugly fits around the carbon electrode t. The zinc electrode is forced down into a strong paper or cardboard container I and the top marginal portions ot the insulating container 8 are turned inwardly 'and downwardly so as to embrace the upper marginal portion of the zinc electrode, as indicated at il.

Hot sealing material Il of asphalt or other desired material is then poured into the cell above the washer so that the down turned end portion of the insulating jacket is embedded therein.

The metal top closure I2 is in the form of an inverted dish and has a socket portion Il adapted to receive the end of the carbon electrode 5 and be crimped thereon. As shown in Figures 1 and 3, the marginal edge portions ci' the closure .are turned downwardly and provided with a bead I4 which forms a shoulder I5. After the top closure has been applied, the sheathed upper end portions of the cell are crimped or spun inwardly so as to llt snugly into the shoulder I5. It has been found that a. tight leak-proof connection is thus provided which has a mechanical strength in excess of the tensile strength of the insulating Jacket.

As will be seen from Figure 1, the top of the cell presents a smooth streamlined appearance and there is no danger of shorting the cell by moisture or conducting material forming an electrical connection between the electrodes at the top of thecell.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom for some modications will be obvious to those skilled in the art.

I claim:

1. A leak-proof dry-cell comprising: a hollow cylindrical zinc electrode containing a centrally disposed carbon electrode, electrolyte and depolarizing mix; a strong fibrous insulating jacket g5 enclosing the side wall of said zinc electrode and having its upper portion turned inwardly and downwardly so as to embrace the uppermarglnal portion of said zinc electrode; and a single rigid metal top closure in the form of an inverted 30 dish having its marginal edge portion tightly Y wardly above the closure to a smaller diameter than said closure.

2. In a dry-cell: a hollow cylindrical zinc electrode; a centrally disposed carbon electrode; a strong fibrous insulating jacket enclosing the side walls of said zinc electrode and having its upper marginal portion turned inwardly and downwardly so as to embrace the upper marginal portion oi the zinc electrode; and a metal topA closure in the form of an inverted dish having a centrally disposed socket embracing and electrically connected to said carbon electrode, the marginal edge portions of the closure being turned downwardly and provided with an outwardly presented bead to provide a shoulder, said closure being tightly locked within the conilnes of said zinc electrode by having the top edge portion of the sheathed zinc bent inwardly above said shoulder.

HOWARD SMITHBACK. 

